The present invention relates in general to computer technologies and in particular to an apparatus for an improved peripheral electronic interconnect device.
The functionality of many modern electronic host devices or hosts (e.g., personal computers, mobile phones, personal digital assistants, game consoles, etc.) can often be expanded by the addition of external devices.
Generally, market adoption of any new technology may be encouraged through the adoption of standards. For example, advances in technology in several areas have converged to bring about high functionality small footprint PC cards. These cards generally use some type of open interface standard (e.g., USB, EXPRESSCARD™, etc.), and are generally configured to communicate through an electronic interconnect device or connector (e.g., peripheral connector, host receptacle connector, etc.).
A common PC card configuration may include a plastic frame for supporting a printed circuit board. Peripheral connectors are typically coupled to one end of the frame for providing an electrical connection to the printed circuit board. Metal or plastic covers are then placed over the frame to shield and protect the printed circuit board. See, for example, U.S. Pat. No. 5,330,360; U.S. Pat. No. 5,339,222; U.S. Pat. No. 5,386,340; and U.S. Pat. No. 5,476,387.
Another type of card configuration does not require the separate plastic frame. In this frameless embodiment, peripheral connectors are separately placed and then soldered to the printed circuit board. The peripheral connectors and the printed circuit board are then covered with top and bottom metallic or plastic covers.
Referring now to FIG. 1, a simplified diagram of a PC card device is shown. Generally, a printed circuit board (PCB) 104 may be coupled to peripheral connector 110, and may be sandwiched between a top cover 102 and a bottom cover 108. As previously stated, plastic frame 106 may be optional in some configurations.
One common open interface standard is Universal Serial Bus (USB). Peripheral devices that implement USB do not generally require a specialized reader host device, but rather can be directly plugged into a USB host connector on a personal computer (PC) or other host device. Included on PC motherboards since 1997, USB is a serial bus architecture in which a USB host controller interface is coupled to the host chipset. USB supports dynamically loadable and unloadable drivers, allowing a user to insert the external device without having to restart the electronic device. The host is able to detect additions, interrogate newly inserted devices, and load appropriate drivers. USB may be commonly used for: wired and wireless LAN, wired PAN, flash memory, flash card adapters, security, legacy I/O (PS2, serial, parallel, optical disk drives, GPS receiver, etc.).
Another more recent standard is PCI Express. PCI Express comprises a multi-drop, parallel bus topology that may contain a host bridge coupled to a CPU, and a switch and several potential endpoints (the I/O devices) coupled to the host chipset. The switch replaces the multi-drop bus and is used to provide fan-out for the I/O bus, providing peer-to-peer communication between different endpoints and this traffic. In addition, because of a relatively low signal-count, simplified and physically smaller point-to-point connections may be constructed with peripheral connectors and cables. PCI Express may be commonly used for: wired LAN, broadband modems, TV tuners/decoders, I/O adapters (e.g., 1394a/b), magnetic disk drives, etc.
In general, peripheral connectors enable the PC card to plug into a port or interface in the host device. Most peripheral and host connectors are either male (containing one or more exposed pins), or a female (containing holes in which the male connector can be inserted). Peripheral and host connectors are commonly comprised of housings and contacts.
Housings protect the peripheral and host connectors against dust, dirt, moisture, electromagnetic interference (EMI), or radio frequency interference (RFI). Housings support contacts to ensure proper mating through keying or polarization and to provide “strain relief” protection to keep peripheral and host connectors united despite accidental pulls or strong vibrations. Mating is the joining of two halves of an electronic interconnect device when a male contact is united with the female contact. Keying is a mechanical means built into a peripheral or host connector housing that indicates the two correct connector halves necessary for mating. Polarization allows only one correct mating alignment of male and female connector halves. The most common metals used for connector contacts are brass, phosphor bronze and beryllium copper. Peripheral and host connector contacts are often plated (e.g., tin, nickel and gold) to increase efficiency and protect against corrosion.
A common contact configuration is stamped/formed. Stamped/formed contacts can be single beam (the receptacle contact holds the plug contact between itself and the housing wall), or dual beam (the female contact holds the male contact between two beams). For example, EXPRESSCARD™ peripheral and host connectors use a type of stamped/formed style called beam-on-blade.
Referring now to FIG. 2, a simplified diagram of a PCI Express configuration for an electronic host device 214 is shown (i.e., PC, PocketPC, mobile phone, PDA, etc.). PCI Express cards may be configured for two card bay configurations 206. ExpressCard/54 202 is typically 54 mm (W)×75 mm (L)×5 mm (H), while ExpressCard/34 204 is typically 34 mm (W)×75 mm (L)×5 mm (H) (these cards are also referred to by engineers and industry publications by the term “ExpressCard” to refer to cards conforming to the standard by the same name). As previously stated, an ExpressCard may be configured to communicate to the host chipset 212 through USB bus 210 or PCI Express bus 208.
Referring now to FIGS. 3A–E, a set of simplified diagrams is shown of an EXPRESSCARD™ peripheral plug connector, at different viewing angles. For purposes of convenience, these three axes have been defined (x, y, z). The x-axis primarily defines width, and hence runs laterally and horizontally across the EXPRESSCARD™, substantially perpendicular to the metal contacts. The y-axis primarily defines height, and hence runs laterally and vertically across the EXPRESSCARD™, and is also substantially perpendicular to both the metal contacts and the x-axis. In addition, the positive direction along the y-axis is toward the top of the EXPRESSCARD™. The z-axis primarily defines length, and hence runs longitudinally across the EXPRESSCARD™, and is also substantially perpendicular to both x-axis and the y-axis. In addition, the positive direction along the z-axis is toward the host device. Subsequently, descriptions of width run along the x-axis, descriptions of height run along the y-axis, and descriptions of length run along the z-axis.
Peripheral plug connector 300 is approximately 34 mm wide, 11 mm long and 5 mm thick. It generally includes lateral guides 302 that allow the user to insert and remove the PC card into receptacle host connector 400, and stopper 312 that generally prevents over insertion of peripheral plug connector 300 into the receptacle host connector 400, as shown in FIGS. 4A–D. Stopper 312 is generally also of a height such that it contacts the bottom surface of receptacle host connector 400 when inserted.
FIG. 3A shows a top isometric view looking at EXPRESSCARD™ peripheral plug connector 300 from rear (PCB side) to the front (host device side), in which a set of metal contacts 310 is exposed, with a height 311 of about 5 mm. As previously described, a peripheral plug connector can both physically and electrically connect a PCB and PC card assembly 306 to a receptacle host connector 400, as shown in FIGS. 4A–D.
Physically, top surface 308 and lateral guides 302 allow PC card assembly 306 to be firmly seated in the receptacle host connector with a specified mating and un-mating force value. In addition, lateral guides 302 also provide finger guides that allow the user to insert and remove the PC card from a host device.
Electrically, the set of metal contacts 310 (or blades) comprise a substantially straight layer for connection to a PCB, and a bended (gull-wing) layer for soldering to PCB substrate. The bended layer may allow the substrate board to be positioned at about the center height position of a PC card. Subsequently, integrated circuits (IC's) or chips and components may be mounted on both top and bottom sides of the PCB substrate.
FIG. 3B shows a top isometric view of peripheral plug connector 300 of FIG. 3A, from the front to the rear (i.e., by rotating the X-Z axis 180 degrees as shown), from the perspective of host device 304.
FIG. 3C shows a bottom isometric view of the peripheral plug connector 300 of FIG. 3A, from the perspective of host device 304. Stopper 312 is shown to prevent peripheral plug connector 300 from being over-inserted into receptacle 400, potentially damaging the set of metal contacts 310.
FIG. 3D shows a bottom isometric view of the peripheral plug connector 300 of FIG. 3A, from the perspective of PCB & PC card assembly 306.
FIG. 3E shows a simplified top down view of the peripheral plug connector perpendicular to the x-z plane. Stopper 312 includes a length 332 and a width 334 that is substantially less than the peripheral plug connector opening width 336.
FIG. 3F shows a simplified side down view of the peripheral plug connector perpendicular to the x-y plane. The peripheral plug connector housing can be functionally divided into three layers: top housing layer 330A, bottom housing layer 330B, and stopper layer 330C. Top housing layer 330A is approximately 2.5 mm in height, and includes the layer of the peripheral plug connector that provides the overhead protection the metal contacts 310 against dust, dirt, moisture, electromagnetic interference (EMI), or radio frequency interference (RFI). It may also provide “strain relief” protection to keep peripheral plug connector and the host receptacle connectors united despite accidental pulls or strong vibrations.
Bottom housing layer 330B includes the layer of the peripheral plug connector that provides the underside protection to the metal contacts 310 against dust, dirt, moisture, electromagnetic interference (EMI), or radio frequency interference (RFI). It may also provide “strain relief” protection to keep peripheral plug connector and the host receptacle connectors united despite accidental pulls or strong vibrations.
Stopper layer includes the layer of the peripheral plug connector that contacts the bottom surface of receptacle host connector 400 when inserted, and prevents over insertion of peripheral plug connector 300 into the receptacle host connector 400, as shown in FIGS. 4A–D. The combined heights of the layers of the peripheral plug connector housing that reside in the bottom housing layer 330B and stopper layer are approximately 2.6 mm.
Referring now to FIGS. 4A–D, a set of simplified diagrams is shown of an EXPRESSCARD™ receptacle host connector. Notice that the orientations shown in FIGS. 4A to 4D are respectively identical to the orientations shown in FIGS. 3A to 3D. FIG. 4A shows a top view of receptacle host connector 400 in which the spring layer of a set of metal contacts 410 (or beams) is exposed. As previously explained, peripheral plug connector 300 and receptacle host connector 400 are designed and built with a set of matching guide rails 302, as shown in FIGS. 3A–E, and guide channels 402 such that they can be easily and accurately mated together. Guide channels 402 provide a substantially U-shaped cavity into which a guide rail 302 may be inserted. Because three sides (350, 352, and 354 of FIG. 3F) of each guide rail 302 are generally in contact with guide channel 402 when the peripheral plug connector and the host receptacle host connector are mated, a specified level of mating and un-mating force is maintained.
FIG. 4B shows a top view of the receptacle host connector 400 of FIG. 4A, from the perspective of host device chipset 404.
FIG. 4C shows a bottom view of the receptacle host connector 400 of FIG. 4A, from the perspective of host device chipset 404.
FIG. 4D shows a bottom view of the receptacle host connector 400 of FIG. 4A, from the perspective of peripheral plug connector 406.
FIG. 4E shows an expanded view of a guide channel 402A, in the x-y plane which is perpendicular to the card longitudinal direction. As previously described, guide channel 402 provide a substantially U-shaped cavity comprising a bottom-height surface 420, a bottom-width-inner surface 422, a height-inner surface 424, a top-inner-width surface 426, and a top-height surface 428.
Referring now to FIG. 5, a simplified diagram of peripheral plug connector 300 is coupled to a receptacle host connector 400. As previously described, receptacle host connector 400 commonly has spring-type metal contacts 410, generally comprising spring-type beam metal contacts that may make physical and electrical contact with a corresponding set of blade metal contacts 310 of peripheral plug connector 300. In addition, stopper 312 generally prevents over insertion of peripheral plug connector 300 into the receptacle host connector 400, as shown in FIGS. 4A–D.
However, as host devices become smaller and are implemented in non-traditional form factors (e.g., mobile phone, digital cameras, watches, etc.) card design flexibility may be substantially advantageous. For example, PC cards which implement the ExpressCard/34 of the specification, with a thickness of about 5 mm, are about half the size of a standard PCMCIA card. Further reductions in size that are still compatible with the appropriate specification would be even more beneficial. For example, in a configuration in which two EXPRESSCARD™ slots are stacked on top of each other, a thinner EXPRESSCARD™ design would allow for the simultaneous use of cards of varying thickness and functionality (i.e., cards that are both less than and greater than 5 mm), as long aggregate thickness as the was less than about 10 mm.
In view of the foregoing, there are desired improved peripheral electronic interconnect device apparatus.